Lesson 3.2: Small Intestine

The next part of the digestive system is the small intestine.  The liquid, partly digested food leaves the stomach and enters the small intestine.  How long do you think the small intestine is?  There is nothing small about the length of it.  The small intestine measures up to 7 m long.  Your small intestine is about 3 times as long as your height!  The small intestine is about 2.5 cm in diameter which is about the diameter of a garden hose.  Read "Small Intestine" on page 208 of your textbook. 

Question 1. What processes occur in the small intestine?

Question 2. What is the first thing that has to happen to the liquefied food that is coming from the stomach into the small intestine?

Question 3. Explain how each of the three nutrients discussed in the reading are digested.

Question 4. Where is bile produced?

 

 

Check your answers with those that follow.

 

 

 

 

 

 

 

 

 

 

 

 

Answers to Questions:

Question 1. What processes occur in the small intestine?

Most of the chemical digestion and absorption of nutrients occurs in the small intestine.

Question 2. What is the first thing that has to happen to the liquefied food that is coming from the stomach into the small intestine?

The first thing that has to happen to the liquefied food that is coming from the stomach into the small intestine is that the acids have to be neutralized.  Contrary to the reading, it is not enzymes that neutralize stomach acids, it is bicarbonate ions produced in the pancreas that neutralize stomach acid.

Question 3. Explain how each of the three nutrients discussed in the reading are digested.

Carbohydrates:  Enzymes in the small intestine complete the breakdown of carbohydrates into sugars.
Protein:  Enzymes in the small intestine break the proteins into smaller components.
Fat:  Bile breaks the fat into small particles, enzymes then complete the breakdown of fat into usable components.

Question 4. Where is bile produced?

Bile is produced in the liver.

 


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